This disclosure relates to implantable, expandable gastric devices. In particular, this disclosure relates to mechanisms and procedures for controlled deflation and explant of such devices.
Many conventional implantable gastric devices have a balloon filled with a biocompatible fluid. Such gastric devices are generally inserted into the stomach when the balloon is deflated and then inflated in vivo. The gastric devices are often left in the stomach for an extended period of time to treat severe obesity or other conditions. The gastric devices are eventually removed after completing the treatment or for other reasons by deflating the balloon, grasping the gastric device with an extraction tool, and extracting the gastric device via the esophagus and mouth. Conventional gastric devices are deflated by attempting to puncture the balloon and aspirate the biocompatible fluid through a needle.
One challenge of deflating conventional devices is that the balloon may rupture when it is punctured by the needle. For example, the balloon typically degrades over time because stomach acids, fungi, and bacteria may degrade the integrity of the balloon wall, and the needle puncture may cause a degraded balloon wall to fail. Also, it is difficult to control the angle between the needle and the balloon, and the needle will tend to rip the balloon as opposed to puncturing the balloon at certain angles. When the balloon ruptures, the biocompatible fluid is quickly expelled into the stomach, which complicates the extraction procedure and may be uncomfortable to the patient. Furthermore, it is believed that uncontrolled rupture of the balloon may permit portions of the balloon to detach, expose interior portions of the device normally contained within the balloon, permit the needle to undesirably engage structures normally contained within the balloon, require additional steps to recover separated components of the balloon or device, or cause discomfort or injury to the patient.
Another challenge of implantable gastric devices is grasping the device for extraction. Several existing devices are grasped by a claw or snare. These procedures can be challenging because projections and/or other features that are easy to grasp may agitate the stomach wall. Thus, there is a need to improve the deflation and extraction of implantable gastric devices.